基于线性溶解能关系预测污染物在被动采样材料与环境介质之间的分配系数

半透膜采样装置(SPMD)作为一种重要的被动采样器,被用于监测有机污染物的环境水平.SPMD的采样材料是置于低密度聚乙烯"口袋"中的三油酸甘油酯.根据有机污染物在被动采样材料与环境介质之间的平衡分配系数(包括被动采样材料/空气分配系数K(sA).和被动采样材料/水分配系数K(sw))值,可估算SPMD的采样速率,也可计...     

Effects of silver nanoparticles with different dosing regimens and exposure media on artificial ecosystem

Due to the wide use of silver nanoparticles (AgNPs) in various fields, it is crucial to explore the potential negative impacts on the aquatic environment of AgNPs entering into the environment in different ways. In this study, comparative experiments were conducted to investigate the toxicological impacts of polyvinylpyrrolidone-coated silver nanoparticles (PVP-AgNPs) with two kinds of dosing regimens, continuous and one-time pulsed dosing, in different exposure media (deionized water and XiangJiang River water). There were a number of quite different experimental results (including 100% mortality of zebrafish, decline in the activity of enzymes, and lowest number and length of adventitious roots) in the one-time pulsed dosing regimen at high PVP-AgNP concentration exposure (HOE) compared to the three other treatments. Meanwhile, we determined that the concentration of leached silver ions from PVP-AgNPs was too low to play a role in zebrafish death. Those results showed that HOE led to a range of dramatic ecosystem impacts which were more destructive than those of other treatments. Moreover, compared with the continuous dosing regimen, despite the fact that higher toxicity was observed for HOE, there was little difference in the removal of total silver from the aquatic environment for the different dosing regimens. No obvious differences in ecological impacts were observed between different water columns under low concentration exposure. Overall, this work highlighted the fact that the toxicity of AgNPs was impacted by different dosing regimens in different exposure media, which may be helpful for assessments of ecological impacts on aquatic environments.     

Photodegradation of 2-(2-hydroxy-5-methylphenyl)benzotriazole (UV-P) in coastal seawaters: Important role of DOM

Benzotriazole UV stabilizers (BT-UVs) have attracted concerns due to their ubiquitous occurrence in the aquatic environment, and their bioaccumulative and toxic properties. However, little is known about their aquatic environmental degradation behavior. In this study, photodegradation of a representative of BT-UVs, 2-(2-hydroxy-5-methylphenyl)benzotriazole (UV-P), was investigated under simulated sunlight irradiation. Results show that UV-P photodegrades slower under neutral conditions (neutral form) than under acidic or alkaline conditions (cationic and anionic forms). Indirect photodegradation is a dominant elimination pathway of UV-P in coastal seawaters. Dissolved organic matter (DOM) from seawaters accelerate the photodegradation rates mainly through excited triplet DOM (³DOM^?), and the roles of singlet oxygen and hydroxyl radical are negligible in the matrixes. DOM from seawaters impacted by mariculture exhibits higher steady-state concentration of ³DOM^? ([³DOM^?]) relative to those from pristine seawaters, leading to higher photosensitizing effects on the photodegradation. Halide ions inhibit the DOM-sensitized photodegradation of UV-P by decreasing [³DOM^?]. Photodegradation half-lives of UV-P are estimated to range from 24.38 to 49.66?hr in field water bodies of the Yellow River estuary. These results are of importance for assessing environmental fate and risk UV-P in coastal water bodies.     

成都市PM2.5和O3复合污染特征及相互作用研究

基于2015—2020年成都市国控环境监测站点逐时大气污染物监测数据,将其分为3类站点（城区、交通、背景站点）,研究不同季节、不同污染水平下,各类站点细颗粒物（PM_2.5）和臭氧（O₃）复合污染特征及相互作用.结果表明：①成都各类站点的PM_2.5超标天数和PM_2.5年平均浓度总体呈下降趋势,背景站点浓度明显小于城区站点和交通站点;O₃年际变化趋势呈波动性,且交通站点和背景站点的变化波动强于城区站点.②各类站点PM_2.5与O₃相关性在O₃污染期（4—8月）和PM_2.5污染期（11—次年1月）均存在显著差异,且二者在不同季节甚至呈现相反的相关性,总体趋势为夏季PM_2.5-O₃的相关性趋于正相关,冬季趋于负相关.③O₃污染期,各类站点二次PM_2.5的浓度和贡献率随光化学水平的升高而增加,而一次PM_2.5日变化幅度差异不大,表现出明显的O₃和PM_2.5协同增长现象.④PM_2.5污染期,PM_2.5与O₃之间并不是简单的线性关系,不同PM_2.5污染程度下,各类站点O₃浓度变化率昼夜波动趋势基本相同,均在12：00—13：00达到峰值,在18：00达到谷值;且随着PM_2.5浓度的增加,O₃浓度变化率峰值/谷值波动范围亦随之增加.     

化学品足迹:概念、研究进展及挑战

化学品污染被联合国环境规划署列为影响人类生存与发展的全球重大环境问题之一。为实现可持续的化学品管理,需定量评价产品生命周期内由化学品排放造成的生态影响。然而,当前的化学品风险评价指标体系往往指向零碎的危害性或毒性终点,未能综合出整体性指标来定量表征生态系统所承受的损害,亦不能衡量人类活动排放的化学品总量与环境承载容量的相对大小。作为环境足迹一员,化学品足迹继承了"足迹"指标的特点,可定量表征生态系统受化学品影响的程度,并结合生态阈值及环境承载容量,有助于评价人类活动对环境可持续性的影响,有望成为公众、企业、决策者及利益相关者之间相互交流的重要工具。本文概述了化学品足迹的基本概念及其发展历程,介绍了现有的化学品足迹计算方法及其应用于不同空间尺度下的案例研究,讨论了化学品足迹研究中存在的问题与挑战,并对其应用前景进行了展望。     

A two-dimensional numerical model for eutrophication in Baiyangdian Lake

Hydrodynamic, physical, and biochemical processes in the Baiyangdian Lake water environment were analyzed comprehensively. An eutrophication ecodynamics model including the effects of reed resistance on flow was coupled with the hydrodynamics governing equations. An improvement on the Water Quality Analysis Simulation Program (WASP, a modeling system introduced by the US Environmental Protection Agency) is established, which uses the zooplankton kinetic equation. The model simulates water quality constituents associated with eutrophication in the lake, including phytoplankton, zooplankton, nitrogen, phosphorus, dissolved oxygen, and others. Various kinetic coefficients were calibrated using measured data or information from relevant literature, to study eutrophication in the lake. The values calculated by the calibrated model agree well with field data, including ammonia nitrogen, total nitrogen, total phosphorus and dissolved oxygen. Changes related to nutrition and dissolved oxygen during the processes were simulated. The present model describes the temporal variation of water quality in Baiyangdian Lake with reasonable accuracy. Deviations between model-simulated and observed values are discussed. As an ideal tool for environmental management of the lake, this model can be used to predict its water quality, and be used in research to examine the eutrophication process.     

酿酒酵母氮代谢物阻遏效应及其对发酵食品安全的影响

综述了国内外发酵食品中氨(胺)类代谢物的研究进展,包括氨基甲酸乙酯的5种形成机制、生物胺和亚硝酸胺的形成机制,阐述了上述生物危害物形成的本质原因——发酵微生物的氮代谢阻遏效应;重点介绍了酿酒酵母胞内5大调控因子(Gln3p、Ure2p、Gat1p、Dal80p和Gzf3p)对其氮源利用的全局调控作用.并以精氨酸和尿素代谢为例,详细介绍了氮代谢阻遏效应的作用机理.酿酒酵母氮代谢物阻遏效应的研究结果,可为解决由于相关含氮有害代谢物积累导致的普遍存在于发酵中的食品安全问题提供理论依据和技术支撑.     

生物膜填料塔启动及烟气脱硫研究

进行了生物膜填料塔挂膜启动及烟气脱硫实验研究。循环液的Fe2+的氧化速率与吸光度有明显的相关性,同时,压力损失和pH也是挂膜启动完成的重要指标。通入低浓度SO2气体驯化后,脱硫率可达到90%以上,Fe2+氧化速率维持在0.2g/(L.h)左右,连续保持7d,挂膜启动完成。脱硫实验结果表明,在SO2入口质量浓度小于2 000m g/m3、喷淋液中Fe2+浓度大于或等于0.06m o l/L、喷淋率约为12L/(m3.h)、空塔气速约为0.15m/s的条件下,脱硫率可达96%以上。当喷淋液循环使用7次后,必须补充新鲜营养液,以保证较高的脱硫率。     

草原区露天煤矿开发景观格局影响回顾性评价——以胜利一号露天矿为例

本文以胜利一号露天矿为例,通过解译近40年来矿区周边的遥感影像图片,对矿区周边的景观类型和景观格局变化进行回顾性评价,结果表明：（1）目前胜利一号露天矿周边景观以草原景观为主,75.41%的景观为草原景观,其中以克氏针茅草原所占面积最大,占整个评价区面积的60.22%,其次为羊草草原景观（占11.58%）。（2）胜利一号露天矿周边景观类型在近40年来发生了明显变化,草原景观不断减少,而人工景观类型却在不断增加2,000年以后人工景观增加幅度最大,2010年人工景观类型面积是2000年的3.54倍。（3）胜利一号露天矿周边土壤质地正逐步由低湿化向中生化和砾石质化转变,草原景观类型也发生了一定变化,与1973年相比2,010年克氏针茅草原面积增加了14.22%,而羊草草原面积却降低了53.6%。（4）人工景观的增加使得矿区周边整个景观更趋于多样化,景观分布也趋于均匀,而景观优势度指数降低,景观斑块密度逐渐增大,最大斑块指数、平均斑块周长面积比、最近邻体距离、蔓延度指数逐渐减小,景观斑块趋于小型化,使景观异质性增加,景观破碎化加大。（5）人工景观的增加使草原景观内部的多样性和均匀度正在遭受破坏;而且随着草原景观中克氏针茅草原面积的不断增加,草原景观的优势度指数不断增加。     

霉变对储存水稻燃烧行为影响的研究

储存水稻火灾危险性研究具有重要意义。通过研究霉变对储存水稻燃烧行为的影响,确定其火灾危险性。锥形量热燃烧实验(Cone Test)结果显示,霉变样品可以在更小的外加辐射下被点燃;在四种热辐射(25 kW/m2,35 kW/m2,45 kW/m2,55 kW/m2)下,霉变样品的着火时间(TTI)与火灾性能指数(FPI)均小于未霉变样品;而火灾蔓延指数(FGI)高于未霉变样品。Cone Test结果表明霉变显著提高了储存水稻的火灾危险性。差示扫描量热仪(DSC)测试发现在低温时霉变样品比未霉变时吸热焓值提高了3.6倍,表明其析出了更多的小分子挥发物。结合气相质谱联用(GC-MS)测试确定了霉变样品析出的挥发物中含有醇类, 酯类和醛类等易燃物。采用稳态管式炉(SSTF)进一步研究储存水稻的充分燃烧行为,结果显示热释放量及烟气毒性与样品质量(20 g,40 g)以及一次进气量(10 L/min,20 L/min,30 L/min)有关,霉变对于两者的影响较小。